Abstract
First-principles calculations are used to investigate the Shockley partial dislocations in 4H-SiC. We show that both dislocations can sustain the asymmetric and symmetric reconstructions along the dislocation line. The latter reconstructions are always electrically active. In particular, the Si(g) 30° partials can explain the optical activation energy for the dislocation glide at ∼2.4 eV above the VB, the narrow peak at 2.87 eV and the broadband at ∼1.8 eV found in photoluminescence spectra. Further, we propose a new model to explain the stability of the symmetric reconstructions and the enhancement of the dislocation velocity in SiC. © The Royal Society of Chemistry.